Brazil's police say they have completed an operation to clear Rio de Janeiro's biggest slum, Rocinha, of drug gangs.

Hundreds of special forces police and navy commandos backed by armoured military vehicles and helicopters moved into the slum before dawn.

The chief of military police said "there were no incidents and no shots were fired" during the operation.

Police are trying to clear Rio's shantytowns of drug gangs ahead of the 2014 World Cup and 2016 Olympics.

Since 2008, they have occupied some 20 slums, or favelas, to drive out the dealers who controlled the areas.

'Historic moment'

"I have the pleasure to inform you that Rocinha and Vidigal [a neighbouring favela] are under our control," chief of military police Alberto Pinheiro Neto told a news conference.

"There were no incidents and no shots were fired. We don't have any information on arrests or weapons seized."

He said the two favelas had been under their control since 06:00 local time (08:00 GMT) and the streets - which had been shut a few hours before the operation began - would soon reopen.

The AFP news agency reported that a few residents watched from their windows as the troops advanced through the deserted streets of Rocinha.

Residents spoken to by the AFP said they supported the move, hoping it would bring better conditions and prospects as well as ridding the favela of criminals.

However, some women were seen crying as the troops moved in, suggesting not everyone supported the operation.

Police had openly announced their plan to move into Rocinha - which is officially home to some 70,000 people, although is widely thought to have considerably more residents.

Some of the favela's residents left the area on Wednesday, as police began setting up checkpoints at entrances to the slum district, which is located close to tourist areas in Rio's south zone.

They scored an early success on Thursday when they arrested alleged drugs kingpin Antonio Francisco Bonfim Lopes - widely known as "Nem" - as he tried to escape Rocinha in the boot of a car.

The driver of the vehicle tried to claim diplomatic immunity, saying he was the honorary consul of the Democratic Republic of Congo, police said.

He then offered a bribe worth $570,000 (£358,000), they added, but officers refused and opened the boot to discover the hidden suspect.

Nem was one of Rio's most wanted suspects and his arrest was described as a "historic moment" by the city's state security secretary Jose Mariano Beltrame.

The police operation to clear the favelas involves special forces, known as BOPE, moving in to take on the traffickers. Police then establish a permanent base in the favela with officers trained in community policing.

City officials also move in to provide services such as healthcare and electricity.

Pacification has been generally welcomed in favelas, where residents have seen a drop in crime.

But there have been complaints about the behaviour of some of the troops and police involved, with local people reporting excessive violence or abuse of authority.